Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
We have already shown how wholly the architecture of all the Italian
lands was, even in its earliest period, pervaded by Greek elements.
Its city walls, its aqueducts, its tombs with pyramidal roofs, and its
Tuscanic temple, are not at all, or not materially, different from the
oldest Greek structures.
No trace has been preserved of any advance
in architecture among the Etruscans during this period; we find among
them neither any really new reception, nor any original creation,
unless we ought to reckon as such the magnificent tombs, e. g. the
so-called tomb of Porsena at Chiusi described by Varro, which vividly
recalls the strange and meaningless grandeur of the Egyptian pyramids.